DIY AO-63 Conversion preset

Verified · 90/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

A DIY conversion of a Hammond AO-63 organ amp for guitar. A 12AX7 preamp based on the Ampeg Gemini II (volume, bass, treble) feeds a 7247 gain stage and phase inverter driving the stock push-pull pair of 7591s with adjustable fixed bias and a GZ34 rectifier. The organ's 7247 reverb driver and recovery are kept with Dwell and Reverb controls, and a 12AX7 adds 6G16 Vibroverb-style bias tremolo with speed and intensity.

• Channels: 1
• Preamp tubes: 2× 12AX7, 3× 7247
• Power tubes: 2× 7591

Tags: diy, american, tremolo, reverb, clean.

Schematic-derived preset files for 16 Fractal and Line 6 modelers: Axe-Fx II/XL/XL+, Axe-Fx III, FM3, FM9, and the full Helix family (Floor, LT, Rack, HX Stomp, HX Stomp XL, Native).

Gridleak extracts amp parameters from original circuit schematics using AI vision — component values, gain staging, tone stack topology, tube types — then generates native preset files for every supported modeler. Every extraction is scored 0–100 and the score is published.